1. Field of Invention
The present invention relates to an optical apparatus, and a projector including a plurality of optical modulation devices which modulate a plurality of color lights in accordance with image information for the respective color lights; and a color synthesizing optical device which synthesizes the color lights modulated by the optical modulation devices and then emits the synthesized light, that are unitarily disposed.
2. Description of Related Art
A related art three-plate type projector includes a color separating optical system which separates a light beam emitted from a light source into color lights in three colors, three optical modulation devices which modulate the respective color lights in accordance with image information, and a color synthesizing optical device which synthesizes the light beams modulated by the respective optical modulation devices.
In such a three-plate type projector, the three optical modulation devices are joined and fixed to the color synthesizing optical device, as stated below, in order to reduce the size of the projector.
A related art optical apparatus, includes for example, a structure having three optical modulation devices that are joined and fixed to a color synthesizing optical device through a plurality of pin spacers. See JP-A-2000-221588.
Each of the optical modulation devices is constructed of an optical modulation element which performs optical modulation, and a holding frame which has an opening in correspondence with an image forming region of the optical modulation element and which houses the optical modulation element therein. Here, a holding frame is formed with four holes in the peripheral edge of the opening. Where the optical modulation element is housed and held in the holding frame, the four pin spacers are respectively inserted through the four holes formed in the holding frame, and the end surfaces of the pin spacers are bonded and fixed to the light-beam incident end surface of a color synthesizing optical device. The side surfaces of the pin spacers and the inner side surfaces of the holes are bonded and fixed, whereby the optical modulation device and the color synthesizing optical device are joined and fixed.
JP-A-2003-121931 discloses, for example, an optical apparatus where the plurality of pin spacers stated above are made unitary.
The optical apparatus includes a holding member which is substantially in the shape of a rectangular plate and which holds a corresponding optical modulation device, and four pins protrude from the surface of the plate outwards of the surface, at the four corner parts of the holding member. In the holding member, the plate surface which couples the four pins is bonded and fixed to the side surface of either of bases mounted on the upper and lower end surfaces of a color synthesizing optical device, or to the end surface of the color synthesizing optical device on the light-beam incident side thereof. In joining and fixing the optical modulation device to the color synthesizing optical device, in a state where the holding member is set on the side surface of the base or the light-beam incident side end surface of the color synthesizing optical device, the optical modulation device is set on the holding member so as to insert the four pins of the holding member through the four holes of the holding frame constituting the optical modulation device. The side surfaces of the four pins and the inner side surfaces of the four holes of the holding frame are bonded and fixed.